Students were allowed to substitute unrelated electives, such as theater, mythology and photography, for core classes in banking, accounting and management.

Raising graduation rates may have been the motive.

Course substitution forms were filed as late as graduation day in past semesters so students could receive diplomas. Edison’s graduation rate historically has been low, with 8 percent of students completing an associate degree program in two years.

Last month, a report showed Edison had climbed from No. 73 to 49 nationally in the number of associate degrees awarded, and a record number of graduates in 2010-11.

Over a five-year period, 2.5 percent of students were allowed to substitute courses; some may have been legitimate. Most inappropriate substitutions were in accounting, business management, and drafting and design.